Multi-temperature refrigerator



Oct. 10, 1961 R. E. LYsEN MULTI-TEMPERATURE REFRIGERATOR Filed June 50, 1958 2 Sheets-Sheet 1 ...n.hullnlllll Il lNvEN-roR /M 2.7/4 Lf BY ATTORNEY Oct. 10, 1961 R. E. LYsEN 3,003,333

MULTI-TEMPERATURE REFRIGERATOR Filed June 30, 1958 2 Sheets-Sheet 2 l l L INVENTOR n.; flauw( 752K ,6J ATTORNEY United States Patent 3,003,333 MULTI-TEMPERATURE REFRIGERATOR Rime Emanuel Lysn, Hasselby, Sweden, assignor tov My invention relates to multi-temperature refrigerators. In household refrigerators of the type having a plurality of compartments thermally insulated from oneV another, it is usually the practice to maintain the compartments at different refrigerating temperatures with at least one of the compartments serving as a freezer section which is adapted to be maintained below freezing temperature. It has already been proposed to provide controls for controlling the diiferent refrigerating temperatures at which several compartments of a household refrigerator are maintained.

The object of my invention is to provide an improved control of simplified construction for controlling the temperatures of compartments of a household refrigerator individually. I accomplish this by connecting in parallel several cooling elements arranged to abstract heat from the different compartments of the refrigerator, the refrigerant from the source of supply being distributed between the several cooling elements, and controlling the flowY of refrigerant to lat least one of the cooling elements by heating a region of its refrigerant supply line to form a vapor lock which prevents flow of refrigerant to such cooling element. 7

The invention, together with the above and other objects and advantages thereof, will become apparent as the following description proceeds, and the features of novelty which characterize my invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

For a better understanding of my invention, reference may be had to the following description taken in connection with the accompanying drawing, in which:

FIG. l is a front elevation of a refrigerator embodying my invention;

FIG. 2 is a perspective view of the refrigerator shown in FIG. 1 with the doors removed, the interior of -the cabinet being indicated in dotted lines to illustrate the invention more clearly;

FIG. 3 is an enlarged fragmentary view of parts shown in FIG. 2;

FIG. 4 is a View Vdriagrarnmatically illustrating the re-` frigeration system shown in FIG. 2; and

FIG. 5 is a fragmentary View similar to FIG. 3 illustrating a modification of a detail.

Referring to FIGS. l Vand 2 of the drawing, I have shown my invention in connection with a household refrigerator comprising a cabinet 11 whose thermally insulated interior is subdivided into a plurality of compartments 12 and 14 one above the other which may be provided with separate doors or closure members 15 and 16, respectively, at the front of the cabinet. The top compartment 12 constitutes the freezer section and is `arranged to be cooled by an evaporator or cooling element 17; while the bottom compartment 14, which constitutes a food storage space in which foods are refrigerated above freezing temperature, is arranged to be cooled by an evaporator or cooling element 18.

The cooling elements or evaporators 17 and 18, which are in the form of looped coils arranged to abstract heat from the compartments 12 and 14 in any suitable man ner, form part of a compression refn'gerating system. As shown in FIGS. 2 and 4, such a system includes a motormotor-compressor unit 19 comprising a casing within ice which `a -motor and compressor are disposed. The motorcompressor unit 19 desirably is located at the rear of the cabinet 11 exteriorly of the thermally insulated compartments 12 and 14. In a system of this type compressed refrigerant gas discharged from the motor-compressor unit 19 iiows through a connection 20 to a condenser 21 in the form of a looped coil having a plurality of heat dissipating elements or cooling fins fixed thereto for cooling the refrigerant by air circulating in thermal exchange relation therewith at the rear of the cabinet l11.

The refrigerant is condensed in the condenser 21 yand flows therefrom to a liquid distributor 22 under the con trol of a small diameter flow-restricting or capillary tube 23. The refrigerant is divided in the liquid distributor 22 with one part thereof flowing through a connection 24'- to the cooling element 17 and the other part thereof `adapted to flow through a connection 25 to the cooling element 18. From the cooling element 17 the refrigerant flows to an accumulator 26 to which the cooling element 18 is also connected by a connection 27. Vaporized refrigerant formed in cooling elements 17 and 18 collects in the accumulator 26 and is Withdrawn by the motorcompressor unit through a suction line 28 which is heat conductively connected along its length to the flow-restricting tube 23.

In the conductors 29 for supplying electrical energy from a source of supply 30 to the motor-compressor unit 19 is connected a switch 31, as shown in FIG. 4, which is thermostatically controlled in any suitable manner responsive to a temperature condition alfected by the cooling element 17. Such a thermostatic control may include -a thermal bulb 32 in thermal exchange relation with the top compartment 12 and a capillary tube 33 connected thereto which are charged with -a suitable volatile fluid and arranged to close and open the switch 31 responsive to rise and fall, respectively, of the temperature of the top freezer section or compartment 12. In this way, the motor-compressor unit can be effectively controlled to maintain the top freezer section 12 in -a `desired low temperature range below freezing temperature.

In accordance with my invention, in order to maintain a higher temperature in the food storage compartment 14 than in the freezer section 12, the connection 25 through which refrigerant is adapted to ow from the liquid distributor 22 to the cooling element 18 is provided with a narrow diameter tube 34 of capillary dimensions through which flow of refrigerant is controlled by the operation of an electrical heater 3S. In the conductors 36 for supplying electrical energy from a source of supply 37 to the electrical heater 35 is connected a switch 38, as shown in FIG. 4 which is thermostatically controlled in any suitable manner responsive to a temperature condition affected bythe cooling element 18. Such a thermostatic control may include a thermal bulb 39 in thermal exchange relation with the bottom compartment 14 and a capillary tube 40 connected thereto which are charged with a suitable Volatile fluid and arranged to open and close the switch 38 responsive to rise and fall, respectively, of the temperature of the bottom food storage compartment 14. When the heater 35 is energized, refrigerant in the narrow diameter tube 34 is vaporized to form -a vapor lock which prevents flow of refrigerant to the cooling element 18 through the connection 25. With this arrangement, the quantity of refrigerant in the cooling element 18 can be effectively controlled to maintain the bottom compartment 18 in a desired temperature range which is higher than that at which the freezer section or compartment 12 is maintained.

It the narrow diameter tube 34 in the connection 25 were omitted, the cooling elements 17 and 18, which are connected in parallel, would operate at substantially the l 3 sametemperature range; and, taking into consideration any differences in-load and in the insulationofthecompartments 12 and 14, these compartments would be maintained approxmiately at the same temperature level. By

providing the tube 34- of capillary dimensions inVv the connection 25 andl electrical'V heater 35y therefor which-V can befintermittently connected to the source of electrical supply 37, the tube 34 canbe heated from time to tin1e t0 vaporize 4refrigerant therein to form a vaporl lock which willi completely stop the ow of refrigerant through'the connection 25 to the cooling element 18.

Under normal operating conditions, a greater amount:V

of-heat must be abstracted from the top compartment or l freezer section 12 than from the bottom food storage comdensate to the cooling element 18 for maintaining the compartrnent 14'ata desired refrigerating temperature.

The quantity of refrigerant actually required for coolingelement 18' is dependent upon the temperature of compartment 14,' and, when this temperature reaches a predetermined low value,.the thermostatic control for the compartment 14, which includes the bulb 39 andftube 40, will function to close switch 38 and connect the heater 35-to the source of electrical supply 37. With this arrangement, a vapor lock is formed in the tube 34, Vas eX- plained above, to prevent dow of refrigerant condensate into cooling element 13 until'the temperature of compartment 14 tends'to rise above the predetermined low value referred' to above, at which time the thermostatic control for thisy compartment will function to render heater 35' inoperable and again allow refrigerant condensate to ow into the cooling element 18.

Since the narrow'diameter tube 34'is provided in the `connection'ZS which is at a region of the path of ow of refrigerant beyond the how-restricting or capillary tube 23, it Willbe understood that the tube V354 does not affect or exercise any control over the flow of refrigerant from the condenser 21 to the liquid distributortZZ. lnFIG. 4, it will bee seen that the tube 34 of'capillary dimensions is; arranged below the liquid distributor 22 so that. when a vapor lock is formed in tube 34, a body of'condensed refrigerant can accumulate in the upper part of the connection 25 which will immediately become available in cooling element 18 when-the heater 35 is shutoff and refrigerant can ilow again* tov the lower coolingelement. While the vertical distance-between the liquid distributor 22'and tube 34`is-not as great in FlG. Zas-in FIG. 4, it will be understoodthat'inpractice the part-of-connection 25 above the capillarytube34 maybe of sufhcientheight to hold an 'adequateVr quantity of condensed-refrigerant which will be availablefon flow to cooling elementk l8` when heater 35 is rendered inoperable.v

AsfshowninFlG. 3, the heater35.may. comprisela hollow sleeve 41`which is held in heatfconductive reiation with thetube4-inanysuitable manner.- The sleeve 41 isg arranged to-receive electrical heat-ing;` cartridge 42 within Whichv-isrdisposed :an electrical heating element 4 may be made without departing from the spirit and scope 0fthe invention, asv pointedv out inthe following claims.

I claim:

1. In a refrigerator having' a thermally insulated ca binet divided into first and second compartments, a refrigerationsystem-comprsing a circuit for circulation of refrigerantincluding a refrigerant translating device, a condenser andirst andvsecond cooling elements-which` are Vconnected in parallel, said lirst and second cooling elea pressure differential between said condenser and saidI vfirst and'second cooling elements which has an inlet c onnected to said-condenser and a single outlet from which all `of the refrigerant isdischarged at the same pressure from said pressure differential maintaining means during operationof' the system, said second section comprising liquid distributingmeans having an inlet connectedto the single-outlet of saidrstsection and two outlets, said Ythird section comprising rst and second supplylines, said ii'rst supply line havingnan inlet connected to one outlet ofsaid-liquid:distributing means and an outlet'con'nected to saidrst cooling element, the second supply line havingan inlet connected to the other outlet of said liquid distributing means and an outlet connected to said second cooling element, means' operatively associated only with saidsecondi supply line for positively controlling flow therethrough of refrigerant discharged from said second section, said control means comprising a conduit of capillary dimensions-in saidsecondsupply line, and means for heating said last-mentioned` conduit, said pressure differential maintaining means and liquid distributing means and said hist supply line being soconstructed and formed that; an unobstructed'path'of ow for refrigerant is always providedfr'om said condenser-to said first cooling element during operation of the system. p

2; Apparatus as set forth in claim l which includes means responsive to a temperature condition affected by saidisecondcooling element for controlling said heating means.

3. Apparatusy as set forthV in claim 1 which includes means responsive to a temperature conditionV aiected by said first cooling element fof controlling said refrigerant translating device, and means responsive to atemperature condition `affected by said second cooling element for controlling said heating means.

4. In a. refrigerator vhavingta thermally insulated cabinet divided into rst andisecond'compartments, a-refrig eration-systemincluding acircuit for `circulation of refrigerant includinga refrigerant translating device, a condenser andrst and second cooling .elements which Aare connected in parallel, said? first and secondcoolingrelements being: arranged to abstract heat fromfsaid first andv second.compartments, respectively,` said circuitV includingv means for maintaining a pressure differential 43 vadapted'to be connected to the conductors-36.` in,

theembodiment joffFlG. 3, the capillary,V tube VE34-is` es sentiallystraightand inheat'conductive relation: withthe sleeve: 41. along`V a verticallyv` extendingv zone thereof.

In.FIG; 5 l'fhave shown another arrangement-Meh differs from that Aillustrated irri-"IG, 3 and justdescribed i11.-tl1 at.the` capillarytubef 34@ provided 1 in 'connection- 25, is in the form of-a helical-coil .disposed about the: sleeve 41 and in good thermal Contact therewith.

While' particular embodiments: ofthe invention have beenshown and-described, it willfbe. apparente-'torinese slnlledfinthe artY that various modifications ,and changesbetween: said condenserl and -said .irst and second-coolingfelements,.liquiddistributing means connected to receivefall ofthe refrigerant from said pressure differential-means, andsupplyYK lines for conducting, refrigerant from Isaidliqui'd. distributing means to said'frst and Ysecondxcoolingfelements, respectively, a conduitl of4 capillary, dimensions l:in-saidrsupply lineto said second coolinggelement, heating-'means'.for heatngsaid conduit, said f liquid distributing means Y- being-.at a: higher: level than netdivided-:into lirseand- :secondV compartments,` a. refrigeration-:fsystemaincluding a circuit yfor circulation of" refrigerant including a refrigerant translating device, a condenser and first and second cooling elements which are connected in parallel, said first and second cooling elements being arranged to abstract heat from said first and second compartments, respectively, said circuit comprising means for maintaining a pressure differential between said condenser and said cooling elements including a how-restricting passage forming means of capillary dimensions, liquid distributing means connected to receive all of the refrigerant from said passage forming means, and supply lines for conducting refrigerant from said liquid distributing means to said rst and second cooling elements, respectively, a conduit of capillary dimensions in said supply line to said second cooling element, heating means for heating said conduit, first thermostatic means for controlling ow of refrigerant condensate through said supply line to said first cooling element, and second thermostatic means completely independent of said first thermostatic means for controlling said heating means.

7. A refrigeration system having a circuit for circulation of refrigerant comprising a high pressure side and a low pressure side and a refrigerant translating device having an inlet for withdrawing refrigerant from the low pressure side at one pressure and an outlet for discharging refrigerant to the high pressure side at a higher pressure, said low pressure side including first and second cooling elements having inlets and outlets, liquid distributing means in the low pressure side of the system which is connected to receive all of the refrigerant from the high pressure side under all operating conditions of the system, supply lines for conducting refrigerant from said liquid distributing means to the inlets of said first and second cooling elements, respectively, means for conducting refrigerant from the outlets of said first and second cooling elements to the inlet of said translating device, said last-mentioned refrigerant conducting means being so constructed and arranged that the outlets of said rst and second cooling elements are always in unobstructed communication with one another in the low pressure side of the system, a conduit of capillary dimensions in said supply line for conducting refrigerant 6 to the inlet of said second cooling element, said supply line for said second cooling element including a section which extends vertically downward from said liquid distributing means to said conduit of capillary dimensions, heating means for heating said conduit, and control means for controlling said heating means.

8. A refrigeration system having a circuit for circulation of refrigerant comprising a high pressure side and a low pressure side and a refrigerant translating device having an inlet for withdrawing refrigerant from the low pressure side at one pressure and an outlet for discharging refrigerant to the high pressure side at a higher pressure, said low pressure side including first and second cooling elements having inlets and outlets, liquid distributing means in the low pressure side of the system which is connected to receive all of the refrigerant from the high pressure side under all operating conditions of the system, supply lines for conducting refrigerant from said liquid distributing means to the inlets of said first and second cooling elements, respectively, means for conducting refrigerant from the outlets of said first and second cooling elements to the inlet of said translating device, said last-mentioned refrigerant conducting means being so constructed and arranged that the outlets of said first and second cooling elements are always in unobstructed communication with one another in the low pressure side of the system, a conduitwof capillary dimensions in said supply line for conducting refrigerant to the inlet of said second cooling element, heating means for heating said conduit, control means for controlling said refrigerant translating device, and control means for controlling said heating means, said control means for controlling said heating means being completely independent of said control means for controlling said device.

References Cited in the le of this patent UNITED STATES PATENTS 2,128,020 Smilack Aug. 23, 1938 2,241,086 Gould May 6, 1941 2,576,663 Atchison Nov. 27, 1951 2,604,761 Atchison July 29, 1952 

